Sinking ship Zynga has lost yet another senior executive, as chief financial officer Dave Wehner abandons the firm for a glittering career at Facebook.

Zynga said that Wehner had resigned for a "senior finance position" at the social network that more or less provides Zynga's revenues.

"Dave remains a good friend to us all and we wish him success in his next role," Zynga head Mark Pincus said in a canned statement.

The company has also recently lost John Schappert, its chief operating officer and Jeff Karp, chief marketing officer in the last few months among other top execs fleeing for the exit as Zynga keeps disappointing with its earnings and its share price heads for rock bottom.

To fill some of the gaping holes in its management team, the social gaming firm said Mark Vranesh, previously chief accounting officer, would take over as CFO and former chief mobile officer David Ko would become COO.

Zynga also moved Barry Cottle out of EVP of business and corporate development and into chief revenue officer and promoted Steven Chiang from EVP of games to president of games.

Pincus said in a note to employees that the employee changes were coming at "an important time".

"We are positioning ourselves for long-term growth and I’m confident that we have the breadth and depth of management talent to deliver on our mission of connecting the world through games," he said.

"With some of our recent game success and the great work that’s being done to move with our players to mobile, we’re making progress. We still have a lot of work to do, but it’s been great to see so many of you step forward to put us on the move again."

Zynga's shares have plummeted since July, when it announced poor second quarter earnings and showed revenues from Facebook had fallen. Without Facebook, Zynga needs to be making money from mobile games, something that's not happening fast enough for investors' liking. The shares have dropped by 58% since July 25, the day it released the results. ®